1. Field of the Invention
The present invention relates to a method of producing perfect-bound or adhesive-bound printed products formed from several printed products, wherein the printed products, which are gathered to form loose book blocks, are fed by means of feeders, which are arranged along a gathering line and are driven at least approximately with synchronous timing, to a conveyance device that has receiving devices that follow one another at regular intervals, and are transferred by this conveyance device into a gluing machine, wherein the event of an interruption of a processing operation, the gluing machine, which is arranged downstream of the conveyance device and also has a conveying function, is run until it is empty.
2. Description of the Related Art
The purpose of book production lines is to gather printed products in the correct order with a gathering machine and then to bind them into book blocks in a gluing machine. If the gathering machine is stopped, the gluing machine should continue to run at least until all of the book blocks present in the conveying clamps of the gluing machine have been processed into crudely bound books. This is necessary, because otherwise the adhesive applied in the spine area of the book block would set and the covers would no longer adhere. In accordance with the prior art, the signatures that have been loosely gathered into book blocks are conveyed by the gathering machine into the gluing machine by means of a so-called separating element, such that the separating element is in a synchronous driving connection with the gluing machine. With each machine cycle, a book block is conveyed by the gathering machine into the gluing machine. If the gathering machine is stopped, the synchronism with the gluing machine is lost, and each additional book block conveyed during the interruption would lead to disturbances in the conveyance into the gluing machine. In installations running at a high speed, in order to be able to uncouple the gathering machine from the gluing machine and brake it, it is therefore necessary first to slow down the entire line to a speed at which trouble-free uncoupling is possible. For this reason, in a design of this type for braking the gathering machine, a braking distance is available which corresponds to the spacing between the book blocks. Again, this can lead to disruptions of the gluing machine.
Another disadvantage manifests itself when the gathering machine, due to a failure of a feeder, must be uncoupled from the gluing machine and stopped. During the entire discharge phase of the gathering machine, several defective book blocks occur downstream of the feeder that is causing the failure and cannot be allowed to be conveyed into the gluing machine in this state. Two methods are known for accomplishing this: All defective book blocks between the gathering machine and the gluing machine are discharged or repaired. Discharging the book blocks has the disadvantage that the unbound book blocks must be taken apart manually or mechanically, sorted into the original printed products, and fed back into the corresponding feeders. If the defective book blocks are repaired in the stopped gathering machine, the repairs can be made manually. Furthermore, during this manual work, production cannot be carried on.
EP 0 337 315 B1 proposes that loose defective book blocks be transferred to a return device by a deflecting device, and that the book blocks then be broken down at least partially into printed products in a separating device.